Practicalities of Impracticability: An Interim Review of Randomized Controlled Trials

Area of Science:

• Bioethics
• Clinical Research Methodology

Background:

• Informed consent is a cornerstone of ethical research.
• Waivers of informed consent are permissible under specific ethical standards, such as impracticability.
• The application of the impracticability standard in randomized controlled trials (RCTs) requires careful examination.

Purpose of the Study:

• To evaluate the fulfillment of the impracticability criterion in RCTs that utilized waivers of informed consent.
• To assess the proportion of participants enrolled without consent in such trials.
• To identify potential issues regarding the justification of impracticability for consent waivers.

Main Methods:

• Systematic review of 155 RCTs using consent waivers.
• Selection of 36 completed RCTs that partially waived informed consent.
• Analysis of recruitment data for 19 of these trials to determine the percentage of participants enrolled without consent.

Main Results:

• An average of 41.6% of participants (range 0.2-98.7%) were enrolled without informed consent across 19 RCTs.
• Six trials enrolled less than 10% of participants without consent.
• Nine trials employed a mixed approach, obtaining consent at some sites while waiving it at others.

Conclusions:

• The widespread use of consent waivers in RCTs raises questions about whether the impracticability standard was consistently met.
• Investigational and ethical review board practices regarding consent waivers warrant further consideration.
• The findings suggest a need for clearer guidelines and stricter adherence to the impracticability criterion in research ethics.